09 — DeFi (Decentralized Finance)

Aplicações financeiras em smart contracts: AMMs, lending, derivatives, stablecoins, RWA, perpetuals, restaking. TVL combinado: ~US$ 200B (mai/2026).

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1. Pilares

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2. AMMs (Automated Market Makers)

Constant-product (Uniswap v1/v2)

$\(x \cdot y = k\)$

Pool com \(x\) tokens A + \(y\) tokens B; produto constante. Swap de \(\Delta x\) tokens A: $\(\Delta y = y - \frac{k}{x + \Delta x \cdot (1 - \text{fee})}\)$

Fee (0.3% Uniswap v2) acumula no pool, beneficiando LPs.

Uniswap v1 (nov/2018)

• Hayden Adams (ex-Siemens engineer).
• ETH ↔ ERC-20 only.
• 0.3% fee.
• Hello-world AMM.

Uniswap v2 (mai/2020)

• Token-token pairs (qualquer ERC-20 ↔ qualquer ERC-20).
• Flash swaps: borrow + return em mesma tx.
• TWAP price oracles built-in.

Uniswap v3 (mai/2021)

• Concentrated liquidity: LPs choose price ranges (capital efficient).
• Fee tiers: 0.05%, 0.3%, 1% (later 0.01%).
• Non-fungible LP positions (NFTs).
• Inspirou copies em todo lugar (PancakeSwap v3, etc.).

Uniswap v4 (jan/2024)

• Hooks: pre/post swap callbacks → custom AMM logic per pool.
• Singleton contract: todos pools em um contrato. Gas saving.
• Flash accounting: net deltas instead of intermediate transfers.
• Hooks enable: dynamic fees, custom oracles, MEV-protection, on-chain limit orders.

Curve

Michael Egorov 2020. Stableswap formula: $\(\sum x_i + (D \prod 1) = ...\text{(invariant blends sum + product)}\)$

Otimizado para assets de preço próximo (USDTUSDCDAI; ETH/stETH). Slippage minimal em meio do range, growth fora.

• CRV: governance token.
• veCRV (vote-escrowed): lock CRV para boost rewards + governance weight. Pioneer "ve-tokenomics".
• Curve Wars: Convex acumulou veCRV → controla emissões → protocols (Frax, Yearn) bid for Convex influence.

Balancer

• Weighted pools (multi-asset, custom weights).
• Stable pools (Curve-like).
• Boosted pools (composable LP).
• CoW Protocol (related entity): batch auction MEV-resistant.

PancakeSwap

BSC primary (later multi-chain). Uniswap fork. Largest DEX em BSC. Cake token.

Aerodrome (Base)

Velodrome fork em Base. ve(3,3) tokenomics. Top DEX em Base — TVL ~US$ 1B.

SushiSwap

Vampire-attacked Uniswap v2 em set/2020. Drama, rollercoaster. Multi-chain, declined.

Maverick, Trader Joe v2.1, Camelot

Concentrated liquidity variations.

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3. Stableswap variants

Specialized for stable assets:

• Curve (above).
• Saddle: Curve fork (defunct as major).
• Ellipsis (BSC Curve fork).

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4. Orderbook DEX

dYdX

• v3 (StarkEx L2, 2021–2023): Top decentralized perp DEX initially.
• v4 (Cosmos appchain, 2023): migrated. Off-chain orderbook + on-chain settle. ~US$ 1B/day volume.

Hyperliquid

• App-specific L1 (custom HyperBFT consensus).
• Top decentralized perp DEX 2024-2026. ~US$ 5-10B daily volume.
• HYPE token TGE nov/2024.

Drift, Vertex, Serum (legacy)

Solana-based orderbook DEXes.

Aevo

Optimistic rollup focused on options + perps.

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5. Lending

Compound (jun/2018)

• Pioneer: floating-rate lending pools.
• COMP token (jun/2020) initiated liquidity mining = DeFi summer.
• Compound III (USDC-base) 2022.

Aave (formerly ETHLend)

• v1 (2020), v2 (2020), v3 (2022).
• Multi-collateral pools.
• Flash loans: borrow + repay em 1 tx (no collateral).
• eMode: same-class assets boosted LTV.
• Isolation mode for new assets.
• Multi-chain.

Morpho

• Morpho Optimizer (legacy): peer-to-peer matching atop Aave/Compound.
• Morpho Blue (jan/2024): minimal isolated lending markets, 650 lines code, immutable.
• MetaMorpho vaults: curated allocations.
• Top growth DeFi 2024-2025. TVL ~US$ 8B.

Spark (MakerDAO)

Aave fork by MakerDAO/Sky. DAI-centric. SubDAO of Sky ecosystem.

Outras

• Euler v2 (relaunched após hack 2023).
• Silo Finance.
• Radiant (omnichain lending via LayerZero).
• Liquity (LUSD stablecoin lending).

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6. Stablecoins

Centralized (custodial)

Crypto-collateralized

Algorithmic / hybrid

USDe (Ethena) — case interessante

Guy Young 2023. Synthetic dollar:

• Holds long ETH spot.
• Shorts ETH perpetual futures (delta-neutral).
• Funding rate revenue → yield to sUSDe stakers.
• Risks: funding rate negative (custos), exchange counterparty (centralized perp venues).

ENA token. ~US$ 5B circulating mid-2026.

Stablecoin GENIUS Act (US, 2025)

Federal framework. Bank-issued stablecoins legitimized. Big banks (JPM, Citi) launching tokens.

Brasil — Drex (CBDC)

Digital Real do Banco Central. Phased rollout 2025-2026. Privacy concerns; regulator-controlled.

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7. Liquid Staking (LSTs)

ETH staked via protocol → liquid wrapped token.

Solana LSTs

• JitoSOL: Jito-Solana validator client + MEV revenue. Top LST Solana.
• mSOL: Marinade.
• bSOL: BlazeStake.

Concerns

• Lido centralization: 30% threshold debated; Vitalik wrote about ETH staking centralization risks.
• Slashing risk: pool slashing affects all stakers.
• Liquidity peg: stETH:ETH peg deviates em stress (mai/2022 LUNA stress: 0.94, recovered).

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8. Liquid Restaking (LRTs)

Wrapping EigenLayer restaked ETH:

Risks

• Recursive leverage: LRT → LP em DeFi → re-collateralized.
• AVS slashing risk propagates.
• De-peg events (jan/2024 ezETH brief de-peg under conditions).

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9. Yield aggregators

• Yearn Finance (YFI): Andre Cronje. Fair-launch 2020 (no premine). Vaults strategically deploy capital.
• Convex (CVX): Curve gauge bribes + boost.
• Aura: Convex-style for Balancer.
• Beefy: cross-chain auto-compounding.
• Pendle: yield tokenization (split principal + yield).

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10. Oracles

Smart contracts can't access off-chain data natively — oracles ponte.

Chainlink

• Largest oracle network. Decentralized aggregator.
• Price feeds: thousands of pairs.
• VRF: verifiable randomness.
• Automation (formerly Keepers): scheduled triggers.
• CCIP: Cross-Chain Interoperability Protocol.
• LINK token.

Pyth Network

• Pull oracle: low-latency price feeds. Originally Solana, now multi-chain.
• Publishers: Jane Street, CBOE, Cumberland, Susquehanna.
• ~400 price feeds, ~80 chains.

RedStone

• Modular oracle. On-demand or push.
• Many integrations em LRT pricing.

API3

• First-party oracles: data providers run own nodes (no aggregator middleman).
• dAPIs.

UMA

• Optimistic oracle: assert + dispute.
• Used by Polymarket for resolution.

Outras

Tellor, DIA, Band, Nest.

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11. RWA (Real-World Assets)

Tokenization de assets tradicionais. Growing fast 2024-2026.

BlackRock BUIDL (US Treasury fund tokenizado)

• Launched mar/2024 em Ethereum.
• US$ 500M+ AUM em 2025.
• Distributed via Securitize.

Ondo Finance (ONDO)

• USDY (yield-bearing US Treasury wrapper).
• OUSG (institutional Treasury).
• US$ 600M+ AUM.

Centrifuge

• Real-estate, invoice financing tokenization.
• Integrated with MakerDAO collateral.

MakerDAO RWA collateral

• ~50% of DAI collateral em RWA (treasuries, US bank loans).
• Sky (rebranded MakerDAO 2024) doubling down.

Backed Finance, Securitize, Polymath

Tokenization platforms.

TVL trend

US\( 8B em 2023 → US\) 50B em 2025 → US$ 100B+ esperado 2026.

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12. Prediction markets

Polymarket

• Polygon-based.
• US$ 3.5B+ volume in 2024 election season.
• USDC-denominated.
• UMA optimistic oracle resolution.
• Banned em US during 2022-2024 CFTC settlement; relaunched US 2025 sob Trump admin.

Kalshi

• US-regulated event exchange (CFTC).
• Not crypto-native but adjacent. Election markets approved 2024.

Augur (legacy)

Pioneer prediction market 2018. Defunct.

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13. Insurance

Nexus Mutual

• Member-owned mutual.
• NXM token.
• Coverages: smart contract, exchange, custody.
• ~US$ 250M cover total active.

Outras

Sherlock, InsurAce, Bridge Mutual, Etherisc.

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14. DAO governance

Snapshot

• Off-chain voting (gasless via signed messages).
• IPFS-hosted proposals.
• Quadratic, weighted, delegations.
• Used by 99% of token-voting DAOs.

Tally

• On-chain executive (after Snapshot vote).
• Governor contract integration.

Safe (Gnosis Safe)

• Multisig wallet standard.
• Used by 95% of DAOs for treasury.

Governance models

• Token-weighted: 1 token = 1 vote. Crítica: plutocracy.
• Quadratic voting: \(\sqrt{\text{tokens}}\) vote weight. Anti-whale.
• Delegated: hold tokens, delegate vote (UNI, COMP, AAVE).
• Conviction voting: longer hold = more weight (1Hive).
• Optimistic governance: pass unless challenged.

Major DAOs

• MakerDAO/Sky: complex, sub-DAOs (SparkDAO, etc.).
• Uniswap DAO: UNI holders. Famously inactive on fee switch debate.
• Aave DAO: GHO, V4, deployments.
• Compound DAO: smaller activity.
• Optimism Collective: Citizens' House (impact attestations) + Token House (technical).
• ENS DAO.
• GitcoinDAO.

Governance attacks

• Beanstalk (apr/2022): flash-loan to acquire 67% voting power → drain treasury (US$ 182M).
• Tornado Cash gov takeover (mai/2023).

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15. Métricas DeFi

TVL (Total Value Locked)

DeFi Llama (defillama.com) is reference. ~US$ 200B (mai/2026). Top chains:

DEX volume

_{US$ 2-5B/day. Uniswap dominante (}40%), seguido Aerodrome, Pancake, Curve.

Perp volume

_{US$ 8-15B/day. Hyperliquid dominante (}50%), dYdX, GMX.

Stablecoin supply

~US$ 250B em 2026. USDT 60%, USDC 25%, restante 15%.

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16. Key Innovations Timeline

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17. Anti-patterns / risks específicos DeFi

❌ Oracle manipulation via flash loan (use Chainlink TWAP, not spot). ❌ Reentrancy em lending (CEI pattern obrigatório). ❌ Front-running em swaps grandes (use private mempool ou TWAP execution). ❌ Slippage protection ausente. ❌ Approval unlimited persistente (use Permit2 / scoped). ❌ Liquidity providing sem entender impermanent loss. ❌ Stake em LRT recursive sem entender slashing exposure. ❌ Yield "100%+ APY" sem fonte real de rendimento (provavelmente Ponzi-token-emission).

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18. Tools / dashboards

• DeFi Llama (TVL, yields, prices).
• Dune Analytics (custom queries).
• Token Terminal (revenue, fees).
• Nansen (on-chain analytics + smart money).
• Arkham (entity labeling).
• Etherscan, Basescan, etc. (block explorers).
• DEXScreener (real-time DEX prices).
• Zerion, DeBank, Zapper (portfolio dashboards).

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19. Referência cruzada

• L1s onde DeFi vive: 04-l1-bitcoin.md, 05-l1-ethereum.md, 06-l1-alt.md.
• L2s scaling DeFi: 07-l2-scaling.md.
• Smart contracts (linguagens, patterns): 08-smart-contracts.md.
• Tokens (governance, vesting): 12-tokenomics.md.
• DeFi hacks: 14-incidentes.md.
• Regulação (SEC vs DeFi, MiCA): 13-regulacao.md.